Stringer

ABSTRACT

A stringer for a modular scaffolding system. The stringer has a lower base, a web extending upwardly from the lower base, and a channel extending upwardly from the web, the channel having at its upper edge a pair of base flanges extending outwardly therefrom and having along a length of its inner wall a flange, wherein an insert shaped complementary to the channel and having a recess disposed along its length complementary to the flange is slidable into the channel.

TECHNICAL FIELD

The following relates generally to structural support members, and more particularly to a stringer.

BACKGROUND

Scaffolding refers to a temporary structure used to support a work crew and some building materials during a construction project. Scaffolding structures generally comprise at least one, but possibly multiple, elevated working surfaces, which are supported by a rigid metal structure formed from a series of posts and beams. The working surfaces are essentially floors upon which workers stand (or sit) and on which building materials can be placed.

The surfaces are formed by a plurality of beams on which a planar base can be fastened. The beams supporting the working surface are also referred to as stringers. A typical stringer is shown in FIG. 1 and has an upper channel within which a wooden or plastic insert is secured. The surface of the floor is generally a sufficiently strong sheet of wood that is fastened to the inserts by nails or screws. Concrete may be poured on top of the sheet in particular applications.

Since the overall scaffold structure is required to have significant rigidity, the inserts must be secured very tightly within the channel through a very tight pressure fit. This means that a worker is required to urge the insert into the channel by use of a mallet or other impact tool. The insert is then fastened by screws/bolts to the beam and this is generally done every 1 to 2 feet to ensure a secure fit. Thus, a significant labor cost is incurred just to apply the inserts. This also makes removal of the insert a laborious task.

Furthermore, as the scaffolding structure is intended to be temporary, the entire structure must eventually be disassembled. The beam and insert structure may be reused a finite number of times but will eventually become overused and not useful for further applications. Since the plastic is pressure fit to the metal beam, it is laborious to remove and, in practice, the entire structure is scrapped rather than separated at great cost in order to be recycled.

An object of the following is to mitigate or obviate at least some of the above disadvantages.

SUMMARY

In one aspect, a stringer for a modular scaffolding system is provided, the stringer comprising: a lower base; a web extending upwardly from the lower base; and a channel extending upwardly from the web, the channel having at its upper edge a pair of base flanges extending outwardly therefrom and having within its inner wall an inner flange; wherein an insert shaped complementary to the channel and having a recess disposed along its length complementary to the flange is slidable into the channel.

In an embodiment, the inner flange extends along substantially the entire length of the channel.

In an embodiment, a pair of inner flanges are provided, one of the inner flanges being provided at each of two inner walls of the channel.

In an embodiment, the pair of inner flanges are mirror images of one another.

In an embodiment, the stringer further comprises an aperture disposed through its sidewalls at one end of the channel.

In an embodiment, the stringer further comprises a second aperture disposed through its sidewalls at the other end of the channel.

In an embodiment, the inner flange is disposed to secure an insert within the channel, the insert having a recess formed therein complementary to the inner flange.

In an embodiment, the insert is an extruded formwork.

In an embodiment, the insert has a pair of recesses formed on opposing sides thereof.

In an embodiment, the insert is formed at a length substantially the same as a length of the stringer.

In an embodiment, the insert is formed at a length substantially the same as a distance between a pair of apertures formed at ends of the stringer.

In an embodiment, the insert is formed from a plastic.

In an embodiment, the insert is a high density plastic.

In an embodiment, the insert is recyclable.

In an embodiment, the insert is formed from recycled garbage bags.

DESCRIPTION OF THE DRAWINGS

A greater understanding of the embodiments will be had with reference to the Figures, in which:

FIG. 1 shows a stringer of the prior art.

FIG. 2 is a front view of an embodiment of the present stringer.

FIG. 3 is a perspective view of an embodiment of the present stringer.

FIG. 4 is a perspective view of an insert.

FIG. 5 is a perspective view of an insert being secured within a stringer.

FIG. 6 is a front view corresponding to FIG. 5 .

FIG. 7 is a perspective view of an alternative approach for securing an insert within a stringer.

DETAILED DESCRIPTION

For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the Figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practised without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.

Various terms used throughout the present description may be read and understood as follows, unless the context indicates otherwise: “or” as used throughout is inclusive, as thoug h written “and/or”; singular articles and pronouns as used throughout include their plural forms, and vice versa; similarly, gendered pronouns include their counterpart pronouns so that pronouns should not be understood as limiting anything described herein to use, implementation, performance, etc. by a single gender; “exemplary” should be understood as “illustrative” or “exemplifying” and not necessarily as “preferred” over other embodiments. Further definitions for terms may be set out herein; these may apply to prior and subsequent instances of those terms, as will be understood from a reading of the present description.

As set out above, an improved stringer is desirable.

Referring now to FIG. 2 and FIG. 3 , a front view of the present stringer is shown. The stringer 100 resembles an I-beam with channels formed at either end of its web. A pair of flanges extend from the lower edge of the downward facing channel 104 and a pair of flanges 106 extend from the upper edge of the upward facing channel 108 to define a lower and upper base, respectively.

The downward facing channel 104 and upward facing channel are joined by the web 110 of the stringer 100.

The present stringer comprises an inner flange 112 formed along an inner wall 116 of substantially the entire length of the upward facing channel 108. In the embodiment shown, a pair of identical flanges 112 is shown, one extending into the channel from each of the upward facing channel's inner walls 116. In other words, the inner flanges 112 are mirror images of one another.

The inner flange permits the use of a prefabricated insert that can be slid into the stringer rather than hammered into the stringer. Thus, the insert can be much more easily and quickly inserted into and removed from the stringer.

The stringer has an aperture disposed through the sidewalls of the upward facing channel at least at one end of the stringer and preferably at both ends of the stringer.

An exemplary insert is shown in FIG. 4 . In the preferred embodiment, the insert 200 is an extruded formwork having a shape complementary to the upper facing channel; that is, generally rectangular in cross section. This permits the fabrication of any desirable length of insert, as a person of skill will appreciate that the stringers are provided in varying lengths.

The insert 200 has formed therein two recesses 202 that are disposed along its sidewalls at a complementary location to the inner flanges 112 of the stringer 100. Thus the recesses 202 are on opposing sides of the insert 200.

As shown in FIG. 5 and FIG. 6 , in use, the insert is formed then slid into the upward facing channel of a stringer along substantially the entire length thereof. An operator then optionally places a drill within one of apertures of the sidewall and drills a hole through the insert so that the drill extends through the opposing aperture of the sidewall. Finally, a bolt 600 is slid through the drilled hole and secured at the opposing end with a nut 602, securing the insert in place. An M6 bolt with M6 locknut is suitable, though other bolt/nut combinations could be used.

Alternatively, as shown in FIG. 7 , in use, the insert is formed then slid into the upward facing channel of a stringer, with the length of the insert being slightly less than the space between the aperture at one end of the stringer and the aperture at the other end of the stringer. An operator then inserts a bolt is through the stringer apertures at both ends to limit movement of the insert without having to drill the insert.

In either case, at the time of disassembly, the nut can be removed, the bolt withdrawn, and the insert can be slid back out of the upward facing channel, or left in if sufficient rigidity remains (for a later project).

The insert 200 is preferably formed from a plastic, and preferably a high density plastic. Preferably, the insert is recyclable. Applicant has determined that it is possible to fabricate the plastic inserts from recycled plastic such as recycled plastic bags, providing an environmentally conscious solution.

Although the foregoing has been described with reference to certain specific embodiments, various modifications thereto will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the appended claims. 

1. A stringer for a modular scaffolding system comprising: a lower base; a web extending upwardly from the lower base; and a channel extending upwardly from the web, the channel having at its upper edge a pair of base flanges extending outwardly therefrom and having within its inner wall an inner flange; wherein an insert shaped complementary to the channel and having a recess disposed along its length complementary to the flange is slidable into the channel.
 2. The stringer of claim 1, wherein the inner flange extends along substantially the entire length of the channel.
 3. The stringer of claim 1, wherein a pair of inner flanges are provided, one of the inner flanges being provided at each of two inner walls of the channel.
 4. The stringer of claim 3, wherein the pair of inner flanges are mirror images of one another.
 5. The stringer of claim 1, wherein the stringer further comprises an aperture disposed through its sidewalls at one end of the channel.
 6. The stringer of claim 5, wherein the stringer further comprises a second aperture disposed through its sidewalls at the other end of the channel.
 7. The stringer of claim 1, wherein the inner flange is disposed to secure an insert within the channel, the insert having a recess formed therein complementary to the inner flange.
 8. The stringer of claim 7, wherein the insert is an extruded formwork.
 9. The stringer of claim 7, wherein the insert has a pair of recesses formed on opposing sides thereof.
 10. The stringer of claim 7, wherein the insert is formed at a length substantially the same as a length of the stringer.
 11. The stringer of claim 7, wherein the insert is formed at a length substantially the same as a distance between a pair of apertures formed at ends of the stringer.
 12. The stringer of claim 7, wherein the insert is formed from a plastic.
 13. The stringer of claim 12, wherein the insert is a high density plastic.
 14. The stringer of claim 12, wherein the insert is recyclable.
 15. The stringer of claim 14, wherein the insert is formed from recycled garbage bags. 